CAE Simulation Study on Thermal Stress of Butterfly Valve and Actuator

2014 ◽  
Vol 532 ◽  
pp. 301-306
Author(s):  
Xiao Bo Tian ◽  
Jin Tang Yang ◽  
Dan Meng
Keyword(s):  
Thermal Stress ◽  
High Temperature ◽  
Temperature Control ◽  
Simulation Study ◽  
Hot Rolling ◽  
Control Measures ◽  
Butterfly Valve ◽  
Hot Air ◽  
Hot Rolled ◽  
Cae Simulation

To the valve system in the furnace hot air duct of the hot-rolled furnace in steel, the thermal Stress of butterfly valve and actuator was simulated by ANSYS. The feasibility of appropriate temperature control measures of too high temperature of butterfly valve and actuator was verified. And in the field, the transformation and the temperature measurement of butterfly valve and actuator were performed; the failure rate was calculated, to ensure that butterfly valve and actuator could meet the requirements of hot rolling.

Study of the Volume Deformation and Stress Development of Concrete Influenced by the Different Cooling Rate

2015 ◽  
Vol 744-746 ◽  
pp. 1495-1498
Author(s):  
Yi Fang ◽  
Xue Feng Song ◽  
Long Chen
Keyword(s):  
Thermal Stress ◽  
Cooling Rate ◽  
Temperature Control ◽  
Control Measures ◽  
Stress And Strain ◽  
Stress Tests ◽  
Volume Deformation ◽  
Cooling Rates ◽  
Stress Development ◽  
Concrete Placement

This paper studied the development of stress and strain influences by different cooling rates based on the concrete thermal stress tests. furthermore, discussed the temperature control measures for early concrete placement.

Hazard Analyses of Fried, Boiled and Steamed Cantonese-Style Foods

1982 ◽  
Vol 45 (5) ◽  
pp. 410-421 ◽  
Author(s):  
FRANK L. BRYAN ◽  
CHARLES A. BARTLESON ◽  
MITSUTO SUGI ◽  
LLOYD MIYASHIRO ◽  
STEVEN TSUTSUMI
Keyword(s):  
Bacillus Cereus ◽  
Water Activity ◽  
Temperature Control ◽  
Room Temperature ◽  
Lethal Effect ◽  
Control Measures ◽  
Foodborne Bacteria ◽  
Hot Air ◽  
Large Numbers ◽  
Rapid Destruction

Time-temperature exposures to which each stage of the preparation of a variety of fried, boiled or steamed Cantonese-style foods were subjected were evaluated at six restaurants. Samples of these foods were examined to determine their water activity, to detect the presence of Bacillus cereus and to count the number of mesophilic aerobic microorganisms. Temperatures of foods that were attained during cooking were usually high enough to cause rapid destruction of vegetative pathogenic foodborne bacteria. Food temperatures usually increased after cooking ended to provide additional lethal effect to any surviving vegetative microorganisms. During hot-holding in steam tables, the temperatures of the foods were such that multiplication of pathogenic foodborne bacteria would be unlikely and would cause additional lethal effect to vegetative forms of these organisms. Foods that were held in hot-air warmers, however, did not always reach sufficiently high temperatures to prevent multiplication of these organisms. Cooked foods were sometimes held at room temperature long enough to permit multiplication of bacteria that might have been present. This was confirmed by the finding of large numbers of mesophilic aerobic microorganisms in samples of such foods. Time-temperature control measures for cooked Cantonese-style foods include: (a) serve these items immediately after cooking or hold them at 55 C (131 F) or higher until served, refrigerated or reheated; (b) cool in layers not exceeding 9 cm (3.5 in) in walk-in refrigerators; and (c) thoroughly reheat cooked, chilled foods or foods left at room temperature to at least 74 C (165 F).

scholarly journals Effect of Hydration Heat Inhibitor on Thermal Stress of Hydraulic Structures with Different Thicknesses

2020 ◽  
Vol 2020 ◽  
pp. 1-17
Author(s):  
Wenqiang Xu ◽  
Sheng Qiang ◽  
Zhengkai Hu ◽  
Bingyong Ding ◽  
Bingyong Yang
Keyword(s):  
Thermal Stress ◽  
Stress Field ◽  
Tensile Stress ◽  
Temperature Control ◽  
Hydration Heat ◽  
Control Measures ◽  
Hydraulic Structures ◽  
Hydration Reaction ◽  
Early Hydration ◽  
External Temperature

Concrete hydration heat inhibitor can inhibit the early hydration reaction of concrete and reduce the initial heat release of concrete. However, there is no in-depth research on the effect of hydration heat inhibitor on hydraulic structures with different thicknesses and constraints. In this paper, numerical simulation is used to study the change of temperature and stress field after adding hydration heat inhibitor by establishing the finite element models of tunnel lining, sluice, and gravity dam. The results show that the effect of the hydration heat inhibitors on reducing the temperature peak is inversely proportional to the thickness of the structure. A formula is put forward to evaluate their relation in this paper. When the thickness of the structure is about 6 m, there is no peak cutting effect. For the stress field, hydration heat inhibitor can greatly reduce the thermal stress of the thin-walled structure and make the structure meet the temperature control requirements; for the medium wall thickness structure, it can reduce the internal tensile stress about 50% and the surface tensile stress about 20%, and other temperature control measures are still needed to ensure that the surface tensile stress of the structure meets the requirements; for hydraulic structures with large volume and thickness, the application effect of the inhibitor has limitations, which can reduce the internal tensile stress about 30%, but the tensile stress in the surface area will increase about 7% due to the increase of the internal and external temperature difference; therefore, other temperature control measures such as arranging cooling water pipe, strengthening surface insulation, and so on are needed to ensure that temperature cracks do not occur. This paper provides references and suggestions for the research and engineering application of hydration heat inhibitor.

Study on Temperature Field and Construction Monitoring of Hydration Heat of Railway Cable-Stayed Bridge Pile Cap

2011 ◽  
Vol 243-249 ◽  
pp. 1589-1596
Author(s):  
Xu Hui He ◽  
Hao Cheng ◽  
Hong Xi Qin
Keyword(s):  
Temperature Field ◽  
Thermal Stress ◽  
Temperature Control ◽  
Structural Reliability ◽  
Control Measure ◽  
Time History ◽  
Hydration Heat ◽  
Control Measures ◽  
Mass Concrete ◽  
Pile Cap

The temperature control of mass concrete is regarded to be a universal problem. Because of the heavy load of railway cable-stayed bridges, the pile caps usually have large dimensions, so the thermal stress, which is caused by hydration heat, must be emphasized. In order to study the spatial distribution of temperature in mass concrete and find a functional temperature control measure during construction, the theoretical and FEM analysis of hydration heat-thermal stress field are applied, which can improve structural reliability and provide reference for design and engineering of the similar project. Based on FEM calculation, the theoretical hydration heat temperature field is obtained. In the same time, the temperature sensors as well as strain sensors are arranged in the key position of pile cap. Then the variation of hydration temperature in concrete would be measured and recorded since the concrete is pouring. According to the theoretical simulation and the monitoring results, the time-history curve of hydration heat is obtained, and the variation of inner temperature gradient along the height direction as well as the longitudinal direction with the concrete age are studied, and the feasibility of temperature control measures is also verified.

Simulation of thermal stress and control measures for rock-filled concrete dam in high-altitude and cold regions

2021 ◽  
Vol 230 ◽  
pp. 111721
Author(s):  
Yuxiang Zhang ◽  
Jianwen Pan ◽  
Xinjian Sun ◽  
Jijun Feng ◽  
Dengqiang Sheng ◽  
...  
Keyword(s):  
Thermal Stress ◽  
High Altitude ◽  
Control Measures ◽  
Concrete Dam ◽  
Cold Regions ◽  
And Control

scholarly journals Research on concrete temperature control measures in deep hole area of super high arch dam

2021 ◽  
Vol 826 (1) ◽  
pp. 012035
Author(s):  
Yuchen Fu ◽  
Yaosheng Tan ◽  
Chunfeng Liu ◽  
Lei Pei ◽  
Yajun Wang ◽  
...  
Keyword(s):  
Temperature Control ◽  
Arch Dam ◽  
Control Measures ◽  
Deep Hole ◽  
High Arch Dam ◽  
Hole Area ◽  
Concrete Temperature

Investigation Into Thermal Stress Characteristics of Pipe-in-Pipe Under High Temperature Condition

2018 ◽  
Author(s):  
Si-Hwa Jeong ◽  
Min-Gu Won ◽  
Nam-Su Huh ◽  
Yun-Jae Kim ◽  
Young-Jin Oh ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Stress ◽  
High Temperature ◽  
Temperature Distribution ◽  
Heat Transfer Analysis ◽  
Piping System ◽  
Curved Pipe ◽  
High Temperature Condition ◽  
Single Pipe ◽  
Radiation Conditions

In this paper, the thermal stress characteristics of the pipe-in-pipe (PIP) system under high temperature condition are analyzed. The PIP is a type of pipe applied in sodium-cooled faster reactor (SFR) and has a different geometry from a single pipe. In particular, under the high temperature condition of the SFR, the high thermal stress is generated due to the temperature gradient occurring between the inner pipe and outer pipe. To investigate the thermal stress characteristics, three cases are considered according to geometry of the support. The fully constrained support and intermediate support are considered for case 1 and 2, respectively. For case 3, both supports are applied to the actual curved pipe. The finite element (FE) analyses are performed in two steps for each case. Firstly, the heat transfer analysis is carried out considering the thermal conduction, convection and radiation conditions. From the heat transfer analysis, the temperature distribution results in the piping system are obtained. Secondly, the structural analysis is performed considering the temperature distribution results and boundary conditions. Finally, the effects of the geometric characteristics on the thermal stress in the PIP system are analyzed.

Ferrite Grain Coarsening from Hot Rolled Austenite in ODS Steels

2013 ◽  
Vol 753 ◽  
pp. 514-517
Author(s):  
Xiao Chao Wu ◽  
Shigeharu Ukai ◽  
Ryota Miyata ◽  
Yoshito Sugino ◽  
Naoko Oono ◽  
...  
Keyword(s):  
Hot Rolling ◽  
Formation Process ◽  
Air Cooling ◽  
Grain Coarsening ◽  
Ferrite Formation ◽  
Temperature Range ◽  
Ods Steels ◽  
Hot Rolled ◽  
Nucleation Growth

The hot rolling at temperature range of 1100 °C to 862 °C and subsequent air-cooling induce a formation of the coarse ferrite grains in the 9CrODS steels. This coarse ferrite is produced by transformation from the severely hot rolled γ-grains to ferrite. Formation process and mechanism of the transformed coarse ferrite are interpreted in terms of a nucleation, growth and coalescence of the same variant ferrite grains under a variant restriction rule.

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